Energy and Angular Distributions of Electrons Ejected from Hydrogen and Helium by 100- to 300-keV Protons

Measurements have been made of the differential cross sections for ejection of electrons of various energies at various angles from hydrogen and helium gases bombarded by 100- to 300- keV protons. After electrostatic analysis, individual electrons were counted using an electron-multiplier detector. Measurements were made at nine angles from 10\ifmmode^\circ\else\textdegree\fi{} to 160\ifmmode^\circ\else\textdegree\fi{} and at electron energies down to 2 eV. Comparison is made with Born-approximation calculations using hydrogen wave functions but with the results scaled to molecular hydrogen and to helium. The Gryzi\ifmmode \acute{n}\else \'{n}\fi{}ski classical theory is also used to calculate cross sections and these are compared with the Born approximation and with the experimental values. A simple semi-empirical equation has been found which fits the energy distributions fairly well at low and intermediate energies.

Hali tarjima qilinmagan